Traffic signaling system



y 1941- 2 c. E. LOMAX 2,249,217

TRAFFIC SIGNALING SYSTEM Filed 001:. 51, 1938 2 Sheets-Sheet l I k s a *3 J k Q 1) v Q 3) INVENTOR. ElaranceELumax W W, QM

ATTORNEYS.

July 15, 1941.

C. E. LOMAX TRAFFIC SIGNALING SYSTEM Filed Oct. 51, 1938 2 Sheets-Sheet 2 I\ Q0 0) M INVENTOR.

Elrs'nce E. Lumax ,M M

ATTORNEYS.

Patented July 15, 1941 UNETE STTES optics TRAFFIC SIGNALING SYSTEM Application October 31, 1938, Serial No. 237,898

10 Claims.

The present invention relates to signaling systems and more particularly to improvements in highway traflic signaling systems wherein traflic control signaling devices located at one or more highway intersections along a highway or street are controlled from a master control station over a line interconnecting the master control station and signaling device switching units located at the respective trafiic lane intersections.

In signalingsystems of the character noted, the plurality of signaling devices locatedat each trafic intersection conventionally comprises a plurality of groups of lamps, each group including red, green and amber signal lamps positioned to face in one traffic approach direction, thereby to give universally recognized indications to ap-' preaching motor vehicle operators or pedestrians. In a four-way intersection, four such groups of lamps are usually provided for properly signaling in each of the four trafiic approach directions. The lamps at each intersection are arranged automatically to be controlled by the apparatus embodied in an associated control box or switching unit, which apparatus functions to energize the lamps in a definite cyclic order. Thus, on a north-south, east-west intersection, the north-south right of way signal lamps are energized for a portion of each operating cycle concurrently with the east-west stop signals. During another portion of each operating cycle, the north-south stop signals are energized concurrently withthe east-west right of way signals. Between the respective portions of each operating cycle during which traiiic right of way is allotted to the respective intersecting trailic lanes are periods conventionally known as change-over intervals during which the amber or caution signals are alone energized or are energized in conjunction with the right of way or stop signals. ;A complete operating cycle of the group of lamps at any intersection includes, therefore, the two periods respectively giving right of way to the two intersecting traflic lanes and two change-over periods. Usually the operating cycles of the signaling devices located at the various intersections are related in a particular manner such that the most expeditious movement of heavy traflic on all intersecting traffic lanes is achieved. The desired relation between the signaling device operating cycles is accomplished by operating the switching apparatus or signaling device control switches embodied in the various switching units in synchronism. With the usual arrangement if a fault develops in the apparatus provided at the master control station or in the line circuit interconnecting the master control station and the various switching units, the signaling device control switches respectively embodied in the switching units cease to operate. As a result the cyclic operation of the signaling devices is arrested and all of the signaling. devices are deenergized or the last energized signaling devices are maintained energized continuously. In either case the control of the tralfic proceeding through each trafiic lane intersection is disrupted.

It is an object of the present invention, therefore, to provide an improved signaling system of the general character briefly described above which is so arranged that .the cyclic operation of the traflic control signaling devices is not permanently arrested in the event of failure of the control :of the associated switching units which is normally exercised over the line circuit interconnecting the switching units and the master control station.

It is another object of the invention to provices, is normally controlled over an incoming line circuit from a master control station, and is so arranged that failure of the control normally exercised over the line circuit does not result in a permanent interruption of the cyclic operation of the associated signaling devices.

It is a further and more specific object of the invention to provide a switching unit of the character briefly described which comprises normally inactive auxiliary control apparatus arranged in an improved manner and operative as a local unit to cause the continued cyclic operation of the associated signaling devices in the event of failure of the control normally exercised over the line circuit incoming to the unit.

In the illustrated embodiment of the inven tion there is provided a master control station which is adapted to control a plurality of switching units respectively provided at the various trafiic lane intersections of a mainhighway over a line circuit extending from the master station to each of the switching units and common to all of the units. Each of the switching units comprises apparatus operative in response to control voltage impressed on the line circuit for In accordance with the present invention nor mally inactive auxiliary control means are provided. for causing the above-mentioned control apparatus to operate, together with apparatus operative in the absence of control voltage on the line circuit for initiating the operation of the auxiliary control means. More particularly, the apparatus embodied in each switching unit comprises a switch including contacts, a wiper associated with the contacts, and a motor for driving the wipers over the contacts; together with circuit connections controlled by the movement of the wiper over the contacts for controlling the energization of the associated signaling devices. Each unit further comprises apparatus including a pair of polarized relays for repeatedly completing the operating circuit of the associated switch motor, thereby to cause the motor to drive the wipers over their associated contacts. The two polarized relays are arranged alternately to operate in response to voltage pulses of alternate opposite polarity impressed on the line circuit and so long as the relays are operating in the proper order the auxiliary control means, mentioned above, remains inactive. A control device in the form of a thermal relay, operative in response to a sustained deenergized condition of both of the polarized relays, is provided for initiating the operation of the auxiliary control means. This auxiliary control means, like the two polarized relays, is operative repeatedly to complete the operating circuit for the associated switch motor, whereby the cyclic operation of the associated signaling devices is continued even though the polarized relays are inactive. In accordance with a further feature of the invention, there is also provided in each unit apparatus operative to arrest the operation of the auxiliary control means in response to the application of a predetermined control voltage to the line circuit which is difierent from that utilized in the normal control of the unit. This apparatus, as embodied in each unit, is also operative to cause the energization of a predetermined one of the signaling devices provided in association with the unit whereby a particular traflic indication is displayed at the controlled intersection.

Further features of the invention pertain to the particular arrangement of the circuit elements whereby the above and additional operating features of the system are attained.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings, in which Figures 1 and 2 illustrate a traiiic signaling system having embodied therein the features of the invention as briefly outlined above.

Referring now to the drawings, the system as illustrated comprises a plurality of switching units, one of which is shown in Fig. 2, a master control station, as shown in Fig. 1, and a line circuit 6 comprising three conductors 1, 8 and 9 interconnecting the control station with each of the switching units. Only one of the switching units, namely that located in proximity to and arranged to control the signaling devices at the trafiic lane intersection I0, is illustrated in detail, but it will be understood that each of the other switching units provided at the other trafiic lane intersections are identical in character with that illustrated. As shown, the signaling devices at the intersection ID of the eastwest highway II and the north-south highway I2 comprise a red signal lamp I3, a green signal lamp I l, and an amber signal lamp I5 arranged to give stop, right of way and caution traffic indications, respectively, to traffic traveling east and west along the highway ll. Also included in the plurality of signaling devices at the intersection ID are the red, green and amber signal lamps I6, I! and i8, respectively, which are arranged to govern trafiic traveling in the north and south directions along the intersecting highway l2. These signaling devices have operating circuits, traced hereinafter, all of which include bus conductors l9 and 20 extending to opposite terminals of any suitable source of commercial frequency current.

For the purpose of energizing the enumerated signaling devices or lamps in a definite cyclic order there is provided in the switching unit of Fig. 2 a cyclically operating switch indicated generally at 2|. This switch comprises three sets of bank contacts 22, 23 and 24 of twenty-four points each and wipers 25, 26 and 21, respectively associated with the contact sets in the order of their enumeration. The enumerated wipers are arranged to be driven by motor means in the form of an alternating current motor schematically indicated at 28. More particularly, the wipers 25, 26 and 21 are carried by and rotatable with a rotary shaft 29 which also carries a ratchet wheel 30 at one end thereof. The motor 28 is provided with a shaft 3! which is arranged to drive a second shaft 32 through an appropriate speed reduction gear mechanism provided in a gear box 34. The shaft 32 carries at one end thereof a cam 35 which is arranged to cause the operation of the ratchet wheel 30 through two steps during each revolution of the shaft 32. More specifically, the cam 35 cooperates with a pawl mechanism comprising a pawl 36 pivoted at 31 on a lever 38, which lever is in turn pivotally mounted at 39 upon any suitable support. The pawl 35 is normaly biased into engagement with one of the peripherally disposed teeth of the ratchet wheel 30 through the action of a coil spring 40. The lever 38 is biased into engagement with the periphery of the cam 35 through the action of a coil spring 4|. In order to actuate the pawl mechanism, the cam 35 is provided with two camming projections 42a and 42b disposed at diametrically opposite points around its periphery. With this arrangement and during clockwise rotation of the shaft 32 in response to operation of the motor 28, the cams 42a and 42b alternately engage the spring biased lever 38. Thus, when the projection 42a, for example, moves against the lever 38, this lever is pivoted about its axis 39 in a clockwise direction to move the pawl 36 to the right so that the ratchet wheel 30 is rotated a predetermined amount in a clockwise direction. As a result, the wipers 25, 26 and 21 are advanced one step or from engagement with one set of contacts into engagement with the next succeeding set of contacts. Thereafter and when the camming projection 42a rides away from the lever 38, the bias exerted on this lever by the spring 4| pivots the lever in a counterclockwise direction so that the pawl 36 is retracted to its cocked position. During continued rotary movement of the cam 35, the wipers 25, 23 and 27 are driven over the contacts of their respective associated sets, in the manner just explained, at the rate of two steps for each revolution of the shaft 32.

The motor 28 includes an operating circuit having three branches arranged respectively to be completed by way of the cam actuated switch springs 43a, 43b and 44a, 44b and the wiper 2'! of the switch 2|. The cams for actuating the indicated springs 43a, 43b and 44a, 4% are mounted for rotation with the stub shaft 32. Thus, there is provided a cam 45 mounted upon the shaft 32 for rotation therewith and having formed therein a camming depression 46 which is arranged to cooperate with the extended reversely bent cam follower portion of the spring ii-lb. A second cam 41, having formed therein a camming depression 48 arranged to receive the reversely bent cam follower portion of the spring 4%, is provided for operating the springs 44s. and 45b. The contact springs 43b and 24s are biased in a direction to disengage their respective associated contact springs 43a and 54a. Hence, when the camming portion of the spring 43b falls into'the depression 45 of the cam G5, the two springs 43a and 33b are moved out of engagement. At any other time when the cam follower portion of the spring 43b engages the peripheral surface of the cam 45, the springs 43a and 43b are operated into engagement. Similarly, the spring Mb engages its associated contact spring 6% at all times exi cept when the follower portion of the spring Mb drops into the depression 48 of the cam 41. The depressions 65 and 43 provided in the cams 45 and 47, respectively, are angularly displaced from each other by an angle of 180 degrees and from the diametrically opposite projections 52a and 42b by an angle of approximately 90 degrees. The purpose of this arrangement will be apparent from the following description of the operation of the switching unit.

The two branches of the operating circuit for the motor 28 which respectively comprise the springs 43a, 43b and the springs 44a, 4% are also arranged to be controlled by polarized relays connected to the conductors of the line circuit 6. More particularly, there is provided a polarized relay 60 having armature springs included in the branch circuit comprising the springs 43a, 43b, and a second polarized relay 50 having armature springs included in the branch circuit comprising the cam controlled springs Ma and 44b. The res spective windings of the two relays 50 and 60 are connected in series across the line conductors 8 and 9 of the line circuit 6 and are so poled that the indicated relays alternately operate in response to voltage pulses 'of alternate opposite polarity impressed across the indicated line conductors.

For the purpose of arresting the operation of the switch 2 l, of deenergizing any energized ones of the signaling devices at the intersection Ill, and of energizing the amber or caution signaling devices provided at this intersection, there is also embodied in the switching unit of Fig. 2 a third polarized relay it having its winding connected across the line conductors l and 8 of the line circuit 6 in series with the winding of a fourth polarized relay 8i! and in a manner such that it only operates in response to the application of voltage of a predetermined polarity between the indicated line circuit conductors. The polarized relay 8% on the other hand, is only operative when voltage of the opposite polarity is impressed across the line conductors 1 and 8' and, in confunctions to maintain a synchronous. relation between the operating cycles of the switch 2| and the other similar switches provided at the other switching units controlled from the master control station of Fig. 1 over the line circuit 6.

In order to change the percentage of each sig-' substantially equal portions of each signaling cycle are allotted for trafi'ic right of way along the highway l2 and along the highway Ii. Operation of this switch is effective to decrease the portion of each signaling cycle during which trains right of way is allotted to the highway ll junction with the switch 2! and the motor 28,

and to increase by a corresponding amount the, period of each cycle during which traihc right of way is allotted to the highway I2.

In accordance with the present invention ther is also embodied in the switching unit illus- I trated in Fig. 2, normally inactive auxiliary control means indicated generally at 15 for controlling the operation of the switch 2|; This auxiliary control apparatus comprises an alternating current motor i5 and means comprising a thermal relay 1! for initiating the operation of the motor 16 in response to a sustained deenergizedcondition of the two polarized relays 5d and 56. The motor 16 includes a shaft which is arranged to drive a stub shaft 9| through the a speed reduction gear'mechanism of a gear box 82. The auxiliary control apparatus 15 also includes a pair of cam controlled switches 92 and v I the switch 93 comprises a movable spring 98 having a cam follower portion biased to engage the peripheral surface of a second cam 99 also mounted for rotation with the stub shaft 9 I. The spring 94 is arranged to engage its associated spring 91 when the portion of greatest radius of the cam 95 engages the cam follower portion'of the spring 94. When, however, the shaft 9! is re tated so that the cam follower portion of ;the, spring 94 engages the portion of the cam 95 of reduced radius, the indicated spring is moved out of engagement with the spring 91 and into engagement with the spring 96. In a similar man ner the spring 98 included in the switch 93 is normally biased out of engagement with its associated springs 63 and 64. When, however, the portions of the cam, 99 of large radius'engage the follower portionof the spring 98, this spring is moved into engagement with its associated contacts 53 and 64. As explained in detail hereinafter, the arrangement is such that with the auxiliary control means 15 operating, alternate erator IOI in synchronism with each of the rotary switches corresponding to and including the switch 2I and embodied in the various switching units which are controlled over the line circuit 0. The rotary switch I may be of any standard commercial construction and comprises two sets of bank contacts I02 and I03 of twenty-four points each, wipers I04 and I05 respectively associated with the contact sets I02 and I03, and means comprising a motor magnet I06 and a ratchet and pawl mechanism, not shown, for driving the enumerated wipers over the contacts of their respective associated sets. The pulse generator IOI is arranged to deliver spaced con trol pulses at two different rates. This generator, which is only diagrammatically shown, may, if desired, take the form of a circuit breaker driven by a synchronous motor through a gear reduction box and arranged intermittently to apply ground potential to the two conductors I01 and I08. In the arrangement illustrated, it is contemplated that the fast pulses shall be applied to the conductor I01 and the slow pulses to the conductor I08. These pulses control the energization of the motor magnet I00 embodied in the switch I00. The switch I00, in turn, functions to apply voltage pulses of alternate opposite polarity between the line conductors 8 and 9 of the line circuit 0. For the purpose of selectively controlling the rate of the pulses delivered to the rotary switch operating magnet I00, there is provided a manually operable switch which includes the switch springs indicated at I00, III] and I I I. In order to interrupt the normal mode of operation of the switching units controlled over the line circuit 0 and to render the units effective continuously to energize the amber or caution signaling devices located at the controlled intersections during the hours when light traffic conditions exist, a second manually operable switch H2 is provided. Current for energizing the operating magnet I05 of the rotary switch I00 is derived from a battery II8. This same current source is also utilized in applying voltage pulses of negative polarity to each of the two line circuit conductors I and 9. In order to apply voltage pulses of the opposite polarity to the line conductors 'I and 9, there is provided a second battery II9. In practice the terminals of the battery H8 are connected to two bus conductors to which certain of the circuit conductors are also connected. In a similar manner the terminals of the battery I I9 are connected to bus conductors to which others of the circuit connections of the master control station extend. For convenience in describing the circuits, however, the two sources of current have been individually indicated in each instance.

Referring now more particularly to the operation of the apparatus and assuming that the elements of the master control station occupy the positions illustrated in the drawings, the ground pulses applied to the conductor I00 are effective to cause the intermittent energization of the rotary switch operating magnet I00 over a circuit extending by way of the conductor I00, the switch springs III, I00 and H4 and the winding of the magnet I00 to the negative terminal of the grounded battery IIB. Each time this magnet is energized over the circuit just traced, it operates in conjunction with its associated ratchet and pawl mechanism to advance the wipers I04 and I05 one'step. With the wiper I04 standing in engagement with its associated first contact, the battery H8 is connected across the line circuit conductors 8 and 9 of the line circuit 6, the negative terminal of this battery being connected to the conductor 9 over a path extending by way of the first contact of the set I02 and the wipe I04 to the conductor 9. Since the odd numbered contacts of the set I02 are all multipled together and connected to the negative terminal of the battery II8, it will be apparent that the path, just traced, is completed each time the wiper I04 is moved into engagement with an odd numbered one of the contacts in the set I 02. On the other hand, when the wiper engages an even numbered contact of the set I02, such, for example, as the second contact, the battery H9 is connected across the line conductors 8 and 9 of the line circuit 0, the positive terminal of this battery being connected to the line conductor 9 over a path substantially similar to that traced above and extending from the negative terminal of the battery H8. Since all of the even numbered contacts of the set I02 are multipled together, positive battery potential is impressed upon the line conductor 9 each time the wiper I04 is moved into engagement with one of its associated even numbered contacts. Thus, during continued operation of the switch I00 voltage pulses of alternate opposite polarity are impressed across the conductors 8 and 9 of the line circuit 0.

With the wiper I04 standing in engagement with any one of its associated odd numbered contacts such that negative battery potential is impressed upon the line conductor 9, the polarized relay 50 provided at the master control station shown in Fig. 2 is energized and assumes its operated position. In a simila manner the relays corresponding to the relay 50 and respectively embodied in the other switching units are also caused to operate. The polarized relay 60 on the other hand, is so poled that it does not operate when the voltage of the battery H8 is impressed between the line conductors 8 and 9. The relay 50, upon operating, opens at its armature 5| a point in the circuit, traced hereinafter, for energizing the heating coil 89 of the thermal relay H. At its armature 52, the relay 50 completes the prepared branch of the operating circuit for the motor 28. More particularly, when the relay 50 operates, the motor 28 is energized over a circuit extending from one terminal of the alternating current source by Way of the conductor 20, the armature 52, the switch spring 44a and 44b, the windings of the motor 28 and the conductor I9 to the opposite terminal of the alternating current source. When energized over this circuit the motor 28 operates to drive the shaft 32 through one-half of a revolution from the position illustrated in the drawings at the end of which the follower portion of the spring 44b drops into the depression 48 and the springs 44a and 44b are disengaged to interrupt the abovetraced operating circuit for the motor 28, Thus, the operation of the motor 28 is arrested. When the shaft 32 is rotated degrees from the position shown in the drawings, the cam 45 is rotated therewith so that the cam follower portion of the spring 43b is moved out of the depression 46. As a result the springs 43a and 431; are moved into engagement to prepare the second branch of the operating circuit for the motor 28. During the movement of the cam 35, the pawl mechanism associated with the ratchet wheel 30 is actuated by the projection 42a so that the wipers f 25, 26 and 21 of the rotary switch 2| are operated one step from the positions shown in the drawings or into engagement with their respective associated second contacts.

When the wiper I04 of the switch it is stepped from engagement with its associated first contact and into engagement with its associated second contact in the manner explained above, the voltage pulse impressed across the line conductors 8 and 9 and derived from the source H8 is terminated, and a voltage pulse of opposite polarity and derived from the source H9 is impressed upon the indicated line conductors. As a consequence, the polarized relay 50 is caused to restore and the polarized'relay B is caused to operate. Similarly, the relays corresponding to the relay 50 and respectively embodied in the other switching units associated with the line circuit 6 are caused to restore and the relays corresponding to the relay 60 are caused to operate. Upon restoring, the relay 5D reprepares, at its armature 5|, the circuit for energizing the heating element 89 of the thermal relay Ti and opens, at its armature 52, a further point in the above-traced branch of the operating circuit for the motor 28. The relay 63, upon operating, opens, at its armature 6!, a second point in the circuit for energizing the heating element 89 of the thermal relay H and completes, at its armature 62, the second branch of the operating circuit for the motor 28, More particularly, when the relay 60 operates, the motor 28 is energized over a circuit which may be traced as extendin from one terminal of the alternating current source by way of the conductor 2! the armature 62, the switch springs 43a and 43:), the windings of the motor 28 and the conductor !9 to the opposite terminal of the alternating current source. When energized over this circuit, the motor 28 again operates to drive the shaft 32 another one-half revolution or back to the position illustrated in the drawings, at which time the cam follower portion of the spring 43b drops into the depression 46 of the cam 45 and the springs 43a. and 43b are disengaged. Thus, the operating circuit for the motor 28 is again interrupted and the operation of the motor is arrested. With the shaft 32 and the cams carried thereby occupying the positions illustrated, it will be observed that the camming projection of the spring 4% is moved out of the depression 43 of the cam 4'! so that the springs 44a and 44b are closed to reprepare the originally traced branch of the operating circuit for the motor 28. During the one-half revolution traversed by the shaft 32, the projection 42b of the cam 30 engages the lever 38 to actuate the pawl mechanism associated with the ratchet wheel 35, so that the ratchet wheel is operated a second step and the wipers of the switch 2! are advanced into engagement with their respective associated third contacts.

From the foregoing description it will be ob vious that the motor 23 is repeatedly energized in response to the alternate operation of the two polarized relays 58 and 50 resulting from the voltage pulses of alternate opposite polarity impressed across the conductors 8 and 9 of the line circuit 6. In this regard. it is pointed out that the duration of the voltage ulses impressed across the line conductors 8 and 9 must be sufficient to permit the motor 28 to drive the shaft 82 through one-half of a revolution each time the motor is energized. With the arrangement shown, it is contemplated that approximately one second shall be required for the motor 23 to drive the shaft 32 one-half of a revolution.

rent source.

This means, of course, that each voltage pulse impressed across the line conductors 8 and 9 must endure for a time interval slightly greater than one second. Preferably, the duration of each voltage pulse is more than two seconds. It willalso be apparent that each time the motor 28 is energized the wipers 25, 26 and 27 of the rotary switch 2! are operated one step. Thus, the wipers of the switch 2!, under normal circumstances, operate in synchronism with the wipers of the switch [lit provided at the master control station. 7

With the switch 82 occupying its normal position, as illustrated in the drawings, the red signal lamp IE for giving a stop trafiic indication to trafiic proceeding along the highway l2 and the green signal lamp I4 for giving a. right of way trafiic indication to trafiio proceeding along the highway II are energized during the interval when the wipers of the switch 2| are traversing the first twelve contacts of their respective associated contact sets. More particularly, the two indicated signal lamps are energized over a circuit which may be traced as extending from one terminal of the alternating current source by way of the conductor 29, the armature H and its associated resting contact, thewiper 25 and the multipled first to twelfth contacts of the contact set 22 to the conductor 51, where it divides, one branch extending by way of the lamp I6 and the conductor l9 to the opposite terminal of the current source and the other branch extending by way of the lamp Hi and the conductor I9 to the opposite terminal of the current source.

r During the interval when the wipers of the switch 2! are traversing their respective eleventh and twelfth contacts, the amber signal lamp 15 which serves to give a caution trafiic indication to trail-- fic proceeding along the highway II is also energized, the circuit for energizing this lamp extending from one terminal of the alternating current source by way of the conductor 20, the wiper 26, the multipled eleventh and twelfth contacts of the contact set 23, the switch springs 88 and 31, the conductor 65, the lamp l5 and the conductor ii) to the opposite terminal of the cur- Thus, during the change-over period just preceding the transfer of traflic right of way from the highway H to the highway l2, the amber or caution signal lamp I5 is energized concurrently with the green signal lamp l4. When the wipers of the switch 2! are moved out of engagement with their respective associated twelfth contacts and into engagement with their respective associated thirteenth contacts, traffic right of way is transferred from the highway II to the highway [2 and the caution signal lamp I5 is deenergized. More particularly, the abovetraced circuit for energizing the two lamps M and I6 is interrupted at the wiper 25 and its associated twelfth contact. Similarly, the abovetraced circuit for energizing the amber lamp I5 is interrupted at the wiper 26 and its associated twelfth contact. During the period when the its associated resting contact, the wiper 25, the multipled thirteenth to twenty-fourth contacts of the contact set 22, the conductor 66, the lamps I1 and I3 in parallel and the conductor I9 to the opposite terminal of the current source. During the interval when the wipers of the switch 2| are traversing their respective associated twenty-third and twenty-fourth contacts, the amber signal lamp I8 is energized to display a caution trafiic indication to traffic proceeding along the highway l2. The circuit for energizing this amber lamp may be traced as extending from one terminal of the alternating current source by way of the conductor 20, the wiper 25, the multipled twenty-third and twenty-fourth contacts of the contact set 23, the conductor 68, the lamp I8 and the conductor I9 to the opposite terminal of the current source. Thus, the amber lamp I8 is energized concurrently with the green lamp I! to indicate to traffic proceeding along the highway I2 that a transfer of right of way to the highway II is about to be effected. This transfer of right of way is effected and a new signaling cycle started when the wipers of the switch 2| are moved out of engagement with their respective twenty-fourth contacts and into engagement with their respective associated first contacts. Thus, when the wiper 25 is disengaged from its associated twenty-fourth contact and is moved into engagement with its associated first contact, the above-traced circuit for energizing the signaling lamps I3 and I1 is interrupted and the previously traced circuit for energizing the lamps I4 and I6 is again completed. Also, when the wiper 26 is moved out of engagement with its associated twenty-fourth contact, the abovetraced circuit for energizing the amber lamp I8 is interrupted. During continued movement of the wipers embodied in the switch 2|, the cycle of operations just described is repeated so that traffic right of way is alternately given to the two intersecting highways II and I2.

As indicated previously, the manually operable switch 82 is provided for the purpose of changing the percentage of each signaling cycle during which traffic right of way is allotted to the two highways II and I2. occupying its normal position, as illustrated in the drawings, the eleventh and twelfth contacts of the contact set 22 are multipled through the springs 83 and 8 3 of the switch 82 to the permanently multipled first to tenth contacts of the contact set 22. Hence, the green lamp I4 and the red lamp I6 are held energized to give traffic right of way to the highway I I, during the interval when the wipers of the switch 2| are traversing the first twelve contacts of their respective associated contact sets. With the switch 82 in this position, the switch springs 81 and 88 are also engaged so that the amber lamp I is only energized when the wipers of the switch 2| are traversing their respective associated eleventh and twelfth contacts. If, however, the switch 82 is operated to its off-normal position, the springs 83 and 84 are disengaged and the springs 83 and 85 are moved into engagement. Through this operation the eleventh and twelfth contacts of the set 22 are disconnected from the permanently multipled contacts numbered from one to ten in the contact set 22 and are connected to the permanently multipled contacts numbered from thirteen to twenty-four in the same contact set. As a result and during movement of the wipers embodied in the switch 2|, the period of each signaling cycle during which traffic right of way Thus, with the switch 82 is given to the highway II is terminated when the wiper 25 is moved out of engagement with its associated tenth contact, whereas the period of each signaling cycle during which trafiic right of way is given to traffic proceeding along the highway I2 is increased to include the time interval when the wipers of the switch 2| are traversing their associated eleventh and twelfth contacts. When the switch 82 is operated to its off-normal position the contact spring 81 is moved out of engagement with its associated spring 88 and into engagement with the contact spring 86. As a result, the multipled ninth and tenth contacts of the contact set 23 are included in the previously traced operating circuit for the amber or caution signal lamp IE'rather than the multipled eleventh and twelfth contacts of this contact set. Hence, the change-over period, during which the amber lamp I5 is energized, is advanced in each signaling cycle to coincide with the last part of the portion of each signaling cycle during which traffic right of way is given to traffic proceeding along the highway II.

From the foregoing description it will be apparent that the switch 2| is synchronously operated with the cycle control switch IEO located at the master control station. Specifically, each time the wipers of the switch ID!) are stepped one step, the wipers of the switch 2| are likewise stepped one step. It is possible that the synchronous relation between the operating cycles of the two switches may be disturbed and in 01'- der to correct any such non-synchronous relation provisions are made for bringing the operated positions of the wipers into coincidence at the end of each operating cycle of the switch I00. To this end a circuit is provided for energizing the polarized relay 8!] each time the switch wiper E5 is driven into engagement with its associated first contact. This circuit may be traced as extending from the positive terminal of the battery 9 by way of the wiper I85 and its associated first contact, the switch springs H5 and H6, the line conductor I, the series connected windings of the relays 10 and and the line conductor 8 to the grounded terminal of the battery I I9. In a similar manner current is caused to flow through the windings of the relays corresponding to the relays I0 and 80 and embodied in the other switching units associated with the line circuit 6. The direction of current flow through the winding of the relay i0 and through the respective windings of the other corresponding relays is such that these relays do not operate. The polarized relay 80 and the other corresponding relays, on the other hand, are caused to operate when energized from the battery ||9 over the line circuit 6. Upon operating, the relay 80 functions to complete the previously referred to third branch of the operating circuit for the motor 28, provided the switch 2| is out of synchronism with the switch I00. More particularly under these circumstances the motor 28 is energized over a circuit extending from one terminal of the alternating current source by way of the conductor 20, the armature 8|, the wiper 21, the multipled second to twenty-fourth contacts of the set 24, the windings of the motor 28 and the conductor I9 to the opposite terminal of the alternating current source. As a result, the motor 28 operates to drive the wipers of the switch 2| until they are moved into engagement with their respective associated first contacts at which time the above-traced operating circuit for the motor 28 is interrupted at the wiper 21. Obviously, if

the relay BB is held energized at the beginning of each operating cycle is sufficient to permit the motor 28 to drive the wipers 25, 26 and 27 over a substantial portion of the contact points embodied in the switch 2 i. It is further pointed out that coincident positions of the wipers respectively embodied in the respective rotary switches of the various switching units may not necessarily represent the desired synchronous relation between the rotary switch operating cycles. For example, if the so-called progressive type of trailic control is utilized, the operating cycles of the switches corresponding to and including the switch 2| are so related that the signaling cycles are started successively and at difierent time intervals at succeeding intersections along the controlled highway. To this end difierent ones of the contacts in the contact sets, corresponding to the contact set 24 of the switch 2|, but provided in the rotary switches of the other switching units controlled over the line circuit 6 may be left unwired. Thus, if four phase progressive traflc control is desired for traiiic traveling east along the highway II, the nineteenth contact of the set corresponding to the contact set 24 in the rotary switch of the unit located immediately east of the intersection it will be left unwired, all other contacts of this set being multipled together. In this assumed case, the thirteenth contact of the contact set corresponding to the set 25 and embodied in the rotary switch of the switching unit located at the intersection two intersections removed in an eastward direction along the highway II from the intersection I!) would be left unwired and all other contacts thereof would be multipled together. Finally, in the assumed case the seventh contact of the contact set corresponding to the set 24 and embodied in the rotary switch of the switching unit located at the intersection three intersections removed in an eastward direction along the highway H from the intersection ill would be left unwired and all other contacts thereof would be multipled together. Thus, by proper selection of the unwired contacts in the respective contact sets corresponding to the contact set 24 but embodied in others of the switching units any desired type of progressive trafic control may be achieved. In such case even though the signaling cycles of the various intersections are displaced in phase, the operating cycles of the rotary switches respectively embodied in the switching units and corresponding to the switch 2| are synchronous and the synchronous relation therebetween is maintained through the provision of the apparatus just described.

As previously indicated, operation of the manually operable switch including the contact springs i69, H0 and III is effective to change the time interval of each signaling cycle. More particularly, with the enumerated contact springs occupying the positions illustrated, the operating magnet We of the switch Hill is energized in directions.

I accordance with the pulses of slow rate impressed upon the conductor Hi8 by the pulse generator lill. When, however, the movable spring N39 is operated out of engagement with the spring Ill and into engagement with the spring H0, the magnet N6 is connected to be energized in accordance with the pulses of fast rate impressed upon the conductor I01 by the generator'l 0 I with the result that the time interval of each signaling cycle is materially reduced. If desired, a clock driven circuit changer may be used in lieu of the manually operable switch, this circuit changer being operative to connect the magnet I96 to be energized in accordance with the pulses of slow rate during certain periods of the day when heavy traiiic conditions exist, and to connect the magnet Hlfi to be energized in accordance with pulses of fast rate during the remaining portions of the day when light trafiic conditions exist.

As pointed out previously, the switch H2 provided at the master control station is utilized for the purpose of interrupting the normal cyclic operation of the switching units associated with the line circuit 6 and causing the caution signaling devices provided at the respective controlled intersections to be energized to display caution signals to traffic proceeding in all traffic approach More particularly, when the switch H2 is operated to its cit-normal position the springs H4 are disengaged to open the previously traced circuit by way of which the rotary switch operating magnet IDS is energized in accordance with the pulse output of the pulse generator I91. Thus, operation of the switch I00 is arrested. When the operation of the switch Hill is arrested, voltage pulses of alternate opposite polarity are no longer impressed across the conductors 8 and 9 of the line circuit 6 and hence operation of the switch 2| and of the other similar switches respectively embodied in the other switching units associated with the line circuit 6 is arrested. It is noted, however, that operation of the switch H2 is ineiiective to remove the voltage of one of the two current sources H8 and H9 from across the indicated line conductors. Thus, if the switch llZ'is operated to its offnormal position immediately after the wipers H34 of the switch N30 has been operated into-engagement with an even numbered contact the voltage of the current source H9 is maintained on the line conductors 8 and 9 and the relay 6% is held operated. By virtue of this arrangement operation of the motor 28 to drive the shaft 32 through a full half of a revolution is insured even though the switch H2 is operated to its offnormal position immediately after the motor 28 starts to operate. Hence, the possibility of the switch liifi being operated one step ahead of the switches corresponding to and including the switch 2! is obviated. When the switch I|2.is operated to its off-normal position, a point is opened, at the springs H5 and H6, in the previously traced path by way of which the synchronizing voltage pulses are impressed between the line conductors I and 8 of the line circuit 6.

At the springs H 6 and H1, an obvious path is.

completed for impressing the voltage of the current source H8 across the conductors l and B of the line circuit 6, the negative terminal of the current source H8 being connected to the line conductor 1. When voltage of this polarity is impressed between the line conductors l and 8, the polarized relay iii of the switching unit illus trated in Fig. 2 is energized and operates. Similarly, the relays corresponding to the relay 10 and respectively embodied in the other switching units also operate. On the other hand, the relay 80 and the other corresponding relays are so poled that they do not Operate when voltage of the polarity indicated is impressed across the line conductors and 8. Upon operating, the relay [9 opens, at the armature H and its associated resting contact, a point in the circuit, traced hereinafter, for energizing the heating element 89 of the thermal relay 11. At the armature TI and its associated resting contact, a point is also opened in the common portion of the previously traced circuits for energizing the signal lamps I3, l4, l and ll, thereby to deenergize the two of these lamps which are energized at the time the switch 2 is operated to its off-normal position. At the armature H and its associated working contact, the relay completes a circuit for energizing the amber signal lamp I8, which circuit may be traced as extending from one terminal of the alternating current source by way of the conductor 29, the armature H, the conductor 68, the lamp l8 andthe conductor l9 to the opposite terminal of the current source. At its armature 12, the relay I9 completes a circuit for energizing the amber signal lamp l5, this circuit extending from one terminal of the alternating current source by way of the conductor 29, the armature 12, the conductor 65, the lamp I5 and the conductor |9 to the opposite terminal of the current source. Thus, any energized ones of the lamps I3, |4, I6 and H are deenergized and the amber signal lamps l5 and I8 are both energized. The last-mentioned lamps are maintained energized until the switch 2 is restored to normal to open the above-traced circuit for energizing the polarized relay 10. Obviously, when the switch 2 is returned to its normal position, the springs H6 and Ill are disengaged to open the above-traced circuit for energizing the relay 19 and the other relays corresponding thereto. As a result, the relay 19 restores to open, at its armatures H and 12, the above-traced circuits for energizing the amber lamps I8 and I5, respectively. At the armature H and its associated resting contact, the circuit for energizing the heating element 89 of the thermal relay 1'! is reprepared and one of the circuits for energizing the signal lamps l4 and IE or the lamps l3 and I7 is recompleted. When the switch H2 is returned to its normal position, the cyclic operation of the rotary switch I90 is resumed with the result that voltage pulses of alternate opposite polarity are again impressed across the line conductors 8 and 9 of the line circuit 6 and the cyclic operation of the switch 2| is again initiated.

Referring now more particularly to the operation of the auxiliary control apparatus 15, it will be recalled from the preceding description that during the normal operation of the apparatus embodied in the switching unit illustrated in Fig. 2, the operating circuit for the thermal relay i1 is interrupted at one of the three armatures 5|, BI and H. If, for some reason, a fault occurs in the system such that both of the polarized relays 59 and 50 are deenergized at a time when they should be operating alternately to complete the tWo previously traced branches of the operating circuit for the motor 28, the above mentioned circuit for energizing the heating element 89 of the thermal relay 1! is completed. This circuit may be traced as extending from one terminal of the alternating current source by way of the conductor 29, the armature H and its associated resting contact, the armatures 6| and 5|, the heating coil 89 and the conductor l9 to the opposite terminal of the current source. When energized over this circuit, the heating coil 89 delivers heat energy to the bimetallic strip 18 with the result that this strip is flexed to the left from the position illustrated in the drawings. After a predetermined time interval the strip 18 is moved into engagement with the contact 79, thereby to complete the operating circuit for the motor 19. The last-mentioned circuit extends from one terminal of the alternating current source by way of the conductor 29, the armatures 1|, 9| and 5|, the bimetallic strip 18, the contact 19, the windings of the motor I9 and the conductor |9 to the opposite terminal of the current source. When energized over this circuit, operation of the motor 16 is initiated and this motor functions to drive the shaft 9| through the speed reducing gear mechanism of the gear box 92. As the two cams and 99 carried by the shaft 9| are rotated, the two branches of the operating circuit for the motor 28 are alternately completed. More particularly, if the cams 95 and 99 are started rotating from the positions illustrated in the drawings, the branch of the operating circuit for the motor 28 which includes the springs 44a and 44b is held prepared at the springs 94 and 9'! of the switch 92. After the cams 95 and 99 have been rotated approximately degrees from the positions shown in the drawings, the cam 99 moves the spring 98 into engagement with the associated contact springs 63 and 64 to complete the last-mentioned branch of the operating circuit for the motor 28. This circuit may be traced as extending from one terminal of the alternating current source by way of the conductor 29, the armatures 1|, 9| and 5|, the bimetallic strip 18, the contact 79, the contacts 64, 93, 53, 94 and 91, the contact springs 44a and 441), the windings of the motor 28 and the conductor l9 to the opposite terminal of the current source. When energized over this circuit, the motor 28 operates in the manner previously explained to drive the shaft 32 through an angle of degrees at which time the cam follower portion of the spring 44b drops into the depression 48 of the cam 41 to open, at the springs 44a and Me, the branch circuit just traced. During the one-half revolution imparted to the shaft 32, the wipers of the rotary switch 2| are advanced one step in the manner previously described. Shortly following the operation of the shaft 32 to its new angular position, the cams 95 and 99 are moved to a point where the cam follower portions of the springs 94 and 98 engage the peripheral surfaces of the two cams 95 and 99, respectively, of reduced radius. During this movement of the cam 95, the spring 94 is moved out of engagement with the spring 91 to open a further point in the above-traced branch of the operating circuit for the motor 28 and into engagement with the spring 96 to prepare the branch of the operating circuit for the motor 28 which includes the springs 43a and 43b. The cam follower portion of the spring 98 drops onto the portion of the cam 99 of reduced radius shortly before the spring 94 is moved into engagement with the spring 99. When this occurs the spring 98 is moved out of engagement with its associated contacts 63 and 94 to open further points in the above-traced branch of the operating circuit for the motor 28. During continued rotary movement of the shaft 9|, the cam 99 again moves the spring 98 into engagement with its associated contact springs 63 and 64, thereby to complete the second branch of the operating circuit for the motor 28. This second branch circuit may be traced as extending from one terminal of the alternating current source by way of the conductor 28, the armatures 1|, BI and the'bimetallic strip 18, the contact 19, the springs 64, 98, 63, 94, 96, 43a and 43, the windings of the motor 28 and the conductor l9 to the opposite terminal of the current source. When energized over this circuit the motor 28 again operates to drive the shaft 32 through another one-half revolution, thereby to causethe wipers of the switch 2| to be advanced an additional step. When the last-mentioned half revolution of the shaft 32 is completed, the cam follower portion of the spring 43b drops into the depression 46 of the cam 45 to open, at the springs 43a and 43b, the second branch of the operating circuit for the motor 28, thereby to arrest the operation of this motor. Also, at the springs 44s. and 44s, the first-traced branch of the operating circuit for the motor 28 is again prepared. Shortly following the last-described operation on the part of the motor 28, the enlarged portion of the cam 95 moves the spring 94 out of engagement with the spring 96 and into engagement with the spring 91. Shortly before the spring 94 is moved into engagement with the spring 96, the cam follower portion of the spring 98 drops onto the portion of the cam 99 of redu ced radius so that this spring is moved out of engagement with the contact springs 63 and-64. Thus, the first branch of the operating circuit for operating circuit for the motor 28. Thus,':the operation of the auxiliary control apparatus is arrested and the motor 28 is controlled in the normal manner as previously explained.

The arrangement of the system is such that if the polarized relay operates at a time when the auxiliary control apparatus is operating the motor 28 is again prepared at the contact springs 44a, 44b, 94 and 91 and is held open at the springs 63, 64 and 98. of the switch 93 until the shaft 9| is driven through an additional 150 degrees. From the foregoing description it will be apparent that so long as the motor 16 continues to operate, the two cam controlled switches 92 and 93 function alternately to complete the two branches of the operating circuit for the motor 28 with the result that the wipers of the switch 2i are driven over the contacts of their associated contact sets and the cyclic energization of the signaling devices l3 to l8, inclusive, is continued. Thus, the provision of the auxiliary control means I5 prevents the traflic control from being disrupted.

If, following operation of the auxiliary control apparatus 15 in the manner just explained, the normal alternate operation of the relays 50 and 68 is resumed, the operation of the auxiliary controlapparatus is arrested and the motor 28 is again controlled through the alternate operation of the two polarized relays. More particularly, when either of the two relays 58 and 60 is caused to operate, a point is opened, at one of the two armatures 5| and 6|, in the common portion of: the two branches of the operating circuit for the motor 28, the operating circuit for the motor 16, and the previously traced circuit for energizing the heating element 89 of the thermal relay 11' Also. during continued alternate operation of the two relays 58 and 68, the arma tures 5i and GI are alternately effective to maintain the common portion of the indicated circuits open. Thus, the operation of the motor 16 is arrested, the heating coil is deenergized and the bimetallic strip 18 assumes its unflexed position out of engagement with the contact 19. With the strip 18 disengaged from the contact 19, a further point is opened in the common portion of the operating circuit for the motor 16 and the two previously traced branches of the the operation of this apparatus is arrested, the operation of the switch 2| is arrested, and the cyclic energization of the signalingdevices provided at the intersection Ill is discontinued. Thus, the relays 58 and 68 may, due to a fault in the line conductor 9, for examp1e,..be' rendered nonresponsive to voltage pulses impressed acrossthe conductors 8 and 9, without affecting the circuit for energizing the polarized relays 10 and 88. In this case, if the manually operable switch I I2 provided at the master control station is operated to its off-normal position to causethe operation of the relay 10 in the manner"previously explained, the relay 18 functions to open, at its armature H and the associated resting contact, a point in the common portion of the two previously traced branch circuits for energizing the motor 28. At this same armature and its associated resting contact, a point'ist also opened in the common portion of above-traced circuit for energizing the heating coil 89 of the thermal relay 1'! and the previously traced circuit for energizing the motor I6. Thus, the.operation of the auxiliary control apparatus Hand of the stepping switch 2| is arrested. Operation of the relay 18 also results in the deenergi zation of any energized ones of the lamps 13,14,

I6 and I1 and the energization of 'the amber signal lamps l5 and I8 in the manner previously explained. Obviously, if the relay 10 is deen-' ergized subsequent to its energizatiori and before the fault responsible for the dormant condition of the two polarized relays 50. and 60 is cleared, operation of the auxiliary control apparatus, 15 is resumed to again'initiate the cyclic energization of the signaling devices provided at themtersection I0. In any case when the operation of the auxiliary control apparatus 15 is arrested and the normal operation of'the switching'appar-atus embodied in the switching unit illustrated in Fig. 2 is resumed, the previously described synchronizing means functions to bring the operating cycles of the various switching units into synchronism.

While there has been described what is at present considered to be the preferred embodi-a ment of the invention, it will be understood that various'modifications may be madetherein, and

it is intended'to cover in the appended claims all such modifications as fall within the true'spirit and scope of the invention.

What is claimed is:

1. A trafiic signaling switching unit adapted to be controlled by way of a line circuit com nected thereto and operative to energize a plurality of traffic signaling devices in' a definite cyclic order, said unit comprising, in combination, a switch including contacts, a Wiper associated with said contacts and'motor means for driving said wipe-r over said contacts, means including circuit connections controlled by the movement of said wiper over said contacts for energizing said signaling devices in said definite cyclic order, an operating circuit for'said motor means, a pair of polarized relays alternately op-" erative in response to voltage pulses of'alterna'te opposite polarity impressed onsaid line circuit,

pleting said operating circuit, thereby to cause said motor means to drive said wiper over. said contacts, normally inactive auxiliary control means also operative repeatedly to complete said operating circuit, and means responsive to a sustained dee'nergized condition of both of said relays for initiating the operation of said auxiliary controlmeans; i v 1 2. A traffic signaling switching unit adapted to be controlled by way'of a line'circuit connected thereto and operative to energize a plurality of traffic signaling devices in a definite cyclic order, said unit comprising, in combination, a. switch including contacts, a wiper associated with said contacts and motor means for driving said wiper over said contacts, means'including circuit connections controlled by the movement of said wiper over said contacts for energizing said signaling devices in said definite cyclic order, an operating circuit for said motor means, a circuit controlling device adapted to be energized by control voltage impressed on said' line circuit, means including said circuit controlling device for completing 's'aid operating circuit, thereby to cause said motor means to drive said wiper over said contacts; auxiliary switching means for completing said operating-circuit, auxiliary motor means for? iactuating' said 3 auxiliary switching means, an operating circuit for said auxiliary motor"means,'and means including said circuit controlling device for completing said last-mentioned operating circuitwhen said circuit controlling device remains deenergized for a sustained time interval. 1 l 3. A traflic signalingswitching unit adapted to bexcontrolled by way'of'aline circuit connected thereto and operative'to energize a plurality of traflici signaling devices in a" definite cyclic order, said. unit comprising, in combination; a switch including contacts, a wiper associated'with'said contacts andmotor means-for driving said wiper over :said contacts, means including circuitcon nectio'ris' controlled by" the movement said wiper over said contacts for energizing said sig-f.

cause said motor means to drive said wiper oversaid contacts, auxiliary switching means for completing said operating circuit, auxiliary motor means for actuating said auxiliary switching means; an operating circuit for said auxiliary motorlmeans, said circuit controlling device being operative, when deenergized, to prepare said lastmentioned operating circuit, and means comprising a thermal relay operativein response to sustained-deenergization of said circuit controlling device. for completing said last-mentioned operating circuit. r g 4,,A trafiic'signaling switching unit adapted to be controlled by way of arline circuit connected thereto, and operative to energize a plurality of associated traffic control signaling devices in a definite cyclic order, said unit comprising, in combination; a switch including contacts, a wiper associated with said contacts and motor means for driving said wiper over said contacts, means including circuit connections controlled by the movement of said wiper over said contacts for energizing said signaling devices in said definite cyclicorder, alpair ofpolarized relays-including windings adapted to: be connected Ito said line circuit, said windings being so poled that one of said relays responds to voltage pulses of one polarity impressed on said line circuit and the other of said relays responds to voltage pulses of opposite polarity impressed on said line circuit, an operating circuit for said motor means, said circuit comprising two branches each including a switch controlled by said motor means, said circuit branches being so connected and arranged that one thereof is completed upon operation of one of said relays and is opened by the motor controlled switch included therein when said wiper is operated through a predetermined movement and the other thereof is prepared at the end'of said predetermined movement, is'completed upon operation of the other of said relays and is opened by the motor controlled switchincluded therein when said wiper is "operated through asecond predetermined movement, nor-' mally'inactive auxiliary control means comprisinga motor and switches individually included in said'branches of said operating circuit, said auxiliary control means being operative alternately to complete said branches of said operat ing circuit in the same order as said relays when said motor is operating, and means responsive to sustained deenergizationof said relays for initiating the operation of said motor. j '5; A trafiic signaling switching unit 'adaptedto be'controlled by way of a line circuit connected thereto and operative to energize a plurality of associated traffic control signaling devices in a definite cyclic order, said unit comprisin in combination, a switch including contacts, a Wiper associatedwith said contacts and motor means for driving said'Wiper over said contacts,'means includingcircuit connections controlled by the movement of said wiper over said contacts for energizing said signaling devices in said definite cyclic order,'a pair of polarized relays including windings adapted to be connected to said line circuit,said windings being so poled that one of said relays responds to voltage pulses. of one polarity impressed on said line circuit and the other of said relays responds to voltage pulses of oppo site polarity impressed on saidlinecircuit, an operating circuit for said motor means,.said circuit comprising two branches eachdncluding a switch controlled by said motor means, aid circ'uit branches being so connected and arranged that-one thereof is completedupon operation of one of'said relays and is opened byg the, motor controlled switch included therein'when said wiper is operated through a predetermined move ment and the other thereof is prepared atthe end of said predetermined movement is coma pleted upon operation of the other of said relays and'is opened by the motorv controlled switch included therein when said wiper is operated through asecond predetermined movement, normally inactive auxiliary control means compris ing a motorand switches individually included in'said branches of said operating circuit, said auxiliary control means being operative alternatelyto complete said branches of said operating circuit in'the same order as said relay when said'rnotor is operating, an operatin circuit for said motor, said relaysbeing operative, whendeenergized to prepare said last-mentioned operating; circuit, and means comprising a thermal relay operative in response to sustained deenergization of said relays for completing'said lastmentioned operating circuit. f

6 A trafii'csig'na-ling switching unitj'aclapted to be controlledby way of a line circuit'connect ed thereto and operative to energize a plurality of associated trafidc control signaling devices in a definite cyclic order, said unit comprising, in combination, apparatus normally operative in response to control voltage of one character impressed on said line circuit for causing the energization of said signaling devices in said definite cyclic order, normally inactive auxiliary control means for causing said apparatus to operate, means operative in the absence of said control voltage on said line circuit for initiating the operation of said auxiliary control means, and means operative to arrest the operation of said auxiliary control means in response to a control voltage of different character impressed on said line circuit.

7. A traific signaling switching unit adapted to be controlled by way of a line circuit connected thereto and operative to energize a plurality of associated traific control signaling devices in a definite cyclic order, said unit comprising, in combination, apparatus normally operative in response to control voltage of one character impressed on said line circuit for causing the energization of said signaling devices in said definite cyclic order, normally inactive auxiliary control means for causing said apparatus to operate, means operative in the absence of said control voltage on said line circuit for initiating the operation of said auxiliary control means, and 2 means operative in response to a control voltage of different character impressed on said line circuit for causing the energization of a predetermined one of said signaling devices and for arresting the operation of said auxiliary control means in the event said auxiliary control means is operating at the time said control voltage of different character is impressed on said line circuit.

8. A trafiic signaling switching unit adapted to be controlled by way of a line circuit connected thereto and operative to energize a plurality of trafiic control signaling devices in a definite cyclic order, said unit comprising, in

combination, a switch including contacts, a wiper tion of said motor means, means responsive to an inactive condition of said first-mentioned control means for initiating the operation of said auxiliary control means, and means operative to arrest the operation of said auxiliary control. means in response to a control voltage of different character impressed on said line circuit.

9. A traffic signaling switching unit adapted to be controlled by Way of a line circuit connected thereto and operative to energize a plurality of traffic signaling devices in a definite cyclic order, said unit comprising, in combination, means including pulse controlled switching apparatus for energizing said signaling devices in said definite cyclic order, a pair of polarized relays alternately operative in response to voltage pulses of alternate opposite polarity impressed on said line circuit, means controlled in accordance with the alternate operation of said relays for transmittingcurrent pulses to said switching apparatus, thereby to cause the operation of said apparatus, auxiliary control means also operative to transmit current pulses to said switching apparatus, said auxiliary control means normally being ineffective to transmit current pulses to said switching apparatus, and means responsive to a sustained deenergized condition of at least one of said relays for rendering said auxiliary control means effective to transmit current pulses to said switching apparatus.

10. A traific signaling switching unit adapted to be controlled by way of a line circuit connected thereto and operative to energize a plurality of trafiic signaling devices in a definite cyclic order, said unitcomprising, in combination, apparatus normally operative in response to control voltage of one character impressed on said line circuit for causing the energization of said signaling devices in said definite cyclic order, auxiliary control means also operative to cause the operation of said apparatus, said auxiliary control means normally being ineffective to cause the operation of said apparatus, means operative in response to the absence of said control voltage on said line circuit for rendering said auxiliary control means effective to cause the operation of said apparatus, and means operative in response to a control voltage of different character impressed on said line circuit for rendering said auxiliary control means ineffective to cause the operation of said apparatus.

CLARENCE E. LOMAX.

-iliary control means for controlling the opera- 

